正如 tyczj 指出的那样,您可以使用接口方法,或者您可以使 datapicker 类成为活动类的内部类,在这种情况下,它应该是静态的,并且您需要外部类的弱引用
使用界面。
在 中定义一个接口DatePickerFragment
。在您的活动类中实现接口并将日期设置为 textview。
public class DatePickerFragment extends DialogFragment
implements DatePickerDialog.OnDateSetListener {
TheListener listener;
public interface TheListener{
public void returnDate(String date);
}
@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
// Use the current date as the default date in the picker
final Calendar c = Calendar.getInstance();
int year = c.get(Calendar.YEAR);
int month = c.get(Calendar.MONTH);
int day = c.get(Calendar.DAY_OF_MONTH);
listener = (TheListener) getActivity();
// Create a new instance of DatePickerDialog and return it
return new DatePickerDialog(getActivity(), this, year, month, day);
}
@Override
public void onDateSet(DatePicker view, int year, int month, int day) {
Calendar c = Calendar.getInstance();
c.set(year, month, day);
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
String formattedDate = sdf.format(c.getTime());
if (listener != null)
{
listener.returnDate(formattedDate);
}
}
}
主要活动
public class MainActivity extends Activity implements DatePickerFragment.TheListener{
Button b;
TextView tv;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
b= (Button) findViewById(R.id.button1);
tv= (TextView) findViewById(R.id.textView1);
b.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
DialogFragment picker = new DatePickerFragment();
picker.show(getFragmentManager(), "datePicker");
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public void returnDate(String date) {
// TODO Auto-generated method stub
tv.setText(date);
}
}
第二种方式不确定这是否是最好的方式。我会推荐上面的接口方法。
public class MainActivity extends Activity {//implements DatePickerFragment.TheListener{
Button b;
TextView tv;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
b= (Button) findViewById(R.id.button1);
tv= (TextView) findViewById(R.id.textView1);
b.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
DialogFragment picker = new DatePickerFragment();
picker.show(getFragmentManager(), "datePicker");
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
public static class DatePickerFragment extends DialogFragment
implements DatePickerDialog.OnDateSetListener {
private WeakReference<MainActivity> mActivity;
@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
// Use the current date as the default date in the picker
final Calendar c = Calendar.getInstance();
int year = c.get(Calendar.YEAR);
int month = c.get(Calendar.MONTH);
int day = c.get(Calendar.DAY_OF_MONTH);
mActivity = new WeakReference<MainActivity>((MainActivity) getActivity());
// Create a new instance of DatePickerDialog and return it
return new DatePickerDialog(getActivity(), this, year, month, day);
}
@Override
public void onDateSet(DatePicker view, int year, int month, int day) {
Calendar c = Calendar.getInstance();
c.set(year, month, day);
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
String formattedDate = sdf.format(c.getTime());
MainActivity target = mActivity.get();
if (target != null) target.tv.setText(formattedDate);
}
}
}